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HelpTest Code GNF7 Factor VII Deficiency, F7 Gene, Next-Generation Sequencing, Varies
Ordering Guidance
Special coagulation testing for factor VII (FVII) activity should be performed prior to any genetic testing. For assessment of FVII activity, order F_7 / Coagulation Factor VII Activity Assay, Plasma.
This test should only be considered if clinical and family history, initial coagulation screens, and/or initial activity tests indicate a diagnosis of FVII deficiency (see Testing Algorithm).
If genetic testing for hereditary bleeding disorders using a larger panel is desired, both a 6-gene focused bleeding panel and a 25-gene comprehensive bleeding panel are available. For more information see GNBLF / Bleeding Disorders, Focused Gene Panel, Next-Generation Sequencing, Varies or GNBLC / Bleeding Disorders, Comprehensive Gene Panel, Next-Generation Sequencing, Varies.
Testing for the F7 gene as part of a customized panel is available. For more information see CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies.
Targeted testing for familial variants (also called site-specific or known mutations testing) is available for the F7 gene. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.
Additional Testing Requirements
All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen as this must be a different order number than the prenatal specimen.
Shipping Instructions
Specimen preferred to arrive within 96 hours of collection.
Necessary Information
Rare Coagulation Disorder Patient Information is required. Testing may proceed without the patient information; however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated
Prenatal Specimens
Due to its complexity, consultation with the laboratory is required for all prenatal testing; call 800-533-1710 to speak to a genetic counselor.
Specimen Type: Amniotic fluid
Container/Tube: Amniotic fluid container
Specimen Volume: 20 mL
Specimen Stability Information: Refrigerated (preferred)/Ambient
Additional information:
1. A separate culture charge will be assessed under CULAF / Culture for Genetic Testing, Amniotic Fluid.
2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Specimen Type: Chorionic villi
Container/Tube: 15-mL tube containing 15 mL of transport media
Specimen Volume: 20 mg
Specimen Stability Information: Refrigerated
Additional Information:
1. A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing.
2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Acceptable:
Specimen Type: Confluent cultured cells
Container/Tube: T-25 flask
Specimen Volume: 2 Flasks
Collection Instructions: Submit confluent cultured cells from another laboratory.
Specimen Stability Information: Ambient (preferred)/Refrigerated
Additional Information:
All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Forms
1. Rare Coagulation Disorder Patient Information (T824) is required.
2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing (Spanish) (T826)
3. If not ordering electronically, complete, print, and send an Coagulation Test Request (T753) with the specimen.
Useful For
Evaluating factor VII deficiency (FVIID) in patients with a personal or family history suggestive of FVIID
Confirming an FVIID diagnosis with the identification of known or suspected disease-causing alterations in the F7 gene
Determining the disease-causing alterations within the F7 gene to delineate the underlying molecular defect in a patient with a laboratory diagnosis of FVIID
Identifying the causative alterations for genetic counseling purposes
Prognosis and risk assessment based on the genotype-phenotype correlations
Carrier testing for close family members of an individual with a diagnosis of FVIID
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CULFB | Fibroblast Culture for Genetic Test | Yes | No |
| CULAF | Amniotic Fluid Culture/Genetic Test | Yes | No |
| MATCC | Maternal Cell Contamination, B | Yes | No |
Testing Algorithm
The clinical workup for factor VII deficiency (FVIID) should begin with special coagulation testing for factor VII (FVII) activity.
Genetic testing for F7D is indicated if:
-FVII activity is less than 65% of normal (Note: reference range may vary depending on the locally established reference range)
-Acquired causes of F7D have been excluded (eg, vitamin K deficiency, use of vitamin K antagonists such as warfarin, liver disease, sepsis)
For prenatal specimens only:
-If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture/genetic test will be added at an additional charge.
-If chorionic villus specimen (nonconfluent cultured cells) is received, fibroblast culture for genetic test will be added at an additional charge.
For any prenatal specimen that is received, maternal cell contamination testing will be performed at an additional charge.
Special Instructions
Method Name
Sequence Capture and Targeted Next-Generation Sequencing (NGS) followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing
Reporting Name
F7 Gene, Full Gene NGSSpecimen Type
VariesSpecimen Minimum Volume
Whole blood: 1 mL; Amniotic fluid: 10 mL; Other specimen types: See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reference Values
An interpretive report will be provided.
Interpretation
All detected variants are evaluated according to American College of Medical Genetics and Genomics recommendations.(10) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.
Clinical Reference
1. Palla R, Peyvandi F, Shapiro AD: Rare bleeding disorders: diagnosis and treatment. Blood. 2015 Mar;125(13):2052-2061
2. Lapecorella M, Mariani G, International Registry on Congenital Factor VII Deficiency: Factor VII deficiency: defining the clinical picture and optimizing therapeutic option. Haemophilia. 2008 Nov;14(6):1170-1175
3. Napolitano M, Siragusa S, Mariani G: Factor VII deficiency: Clinical phenotype, genotype and therapy. J Clin Med. 2017 Mar 28;6(4):38
4. Mariani G, Herrmann FH, Schulman S, International Factor VII Deficiency Study Group, et al: Thrombosis in inherited factor VII deficiency. J Thromb Haemost. 2003 Oct;1(10):2153-2158.
5. de Moerloose P, Schved J-F, Nugent D: Rare coagulation disorders: fibrinogen, factor VII and factor XIII. Haemophilia 2016. Jul;22 Suppl 5:61-65
6. Quintavalle G, Riccardi F, Rivolta GF, et al: F7 gene variants modulate protein levels in a large cohort of patients with factor VII deficiency. Results from a genotype-phenotype study. Thromb Haemost. 2017 Aug 1;117(8):1455-1464
7. da Silva VA, Silva SS, Martins FF: Acquired deficiency of coagulation factor VII. Rev Bras Hematol Hemoter. 2015 Jul- Aug;37(4):269-271
8. Mulliez SM, Devreese KM: Isolated acquired factor VII deficiency: a review of the literature. Acta Clin Belg. 2016 Apr;71(2):63-70
9. Mumford AD, Ackroyd S, Alikhan R, et al: Guideline for the diagnosis and management of the rare coagulation disorders: a United Kingdom Haemophilia Centre Doctors' Organization guideline on behalf of the British Committee for Standards in Haematology. Br J Haematol. 2014 Nov;167(3):304-326
10. Richards S, Aziz N, Bale S, et al; ACMG Laboratory Quality Assurance Committee: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-424
Day(s) Performed
Varies
Report Available
28 to 42 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81479
88233-Tissue culture, skin, solid tissue biopsy (if appropriate)
88240-Cryopreservation (if appropriate)
88235-Amniotic fluid culture (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GNF7 | F7 Gene, Full Gene NGS | 94235-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 619090 | Test Description | 62364-5 |
| 619091 | Specimen | 31208-2 |
| 619092 | Source | 31208-2 |
| 619093 | Result Summary | 50397-9 |
| 619094 | Result | 82939-0 |
| 619095 | Interpretation | 59465-5 |
| 619096 | Additional Results | 82939-0 |
| 619097 | Resources | 99622-3 |
| 619098 | Additional Information | 48767-8 |
| 619099 | Method | 85069-3 |
| 619100 | Genes Analyzed | 82939-0 |
| 619101 | Disclaimer | 62364-5 |
| 619102 | Released By | 18771-6 |